Fig. 2
From: Interface-mediated hygroelectric generator with an output voltage approaching 1.5 volts
Preparation and characterization of heterogeneous graphene oxide. (a) Schematic illustration of the preparation process of heterogeneous graphene oxide (h-GO)-based hygroelectric generator (HEG). h-GO is composed of gradient reduced graphene oxide (grGO) with compact interlayer spacing and graphene oxide (GO). (b) Cross-sectional scanning electron microscopy (SEM) image of h-GO. Inset b is the sectional-viewed optical image of h-GO. Scale bars: b, 20 μm; inset, 0.2 mm. (c) Energy-dispersive spectroscopy (EDS) along the transversal direction of h-GO indicates a chemical C/O ratio gradient within the grGO, while a nearly constant C/O ratio through the GO region. (d) X-ray diffraction (XRD) pattern of top side (grGO) and bottom side (GO) of h-GO
